Ag Corner

Tuesday, October 2, 2007

Fall Applied Weed Control For Field and Yard

Fall is an ideal time for perennial weed control. This is true for both the home garden and farm.

Home/Garden Fall Weed Control

Early and mid October is a great time to control dandelions in the lawn and garden. Dandelion is a perennial that is mechanically difficult to control. When dandelion tap roots are cut, one ends up with two rather than one dandelion. Once most vegetable gardens are froze out or finished for the year, products containing 2,4-D (there are many but Weed-B-Gone is one) can be applied in the fall to control these and other broadleaf perennials. For larger yards, a gallon jug of 2,4-D at a farm supply store may be the most economical source. Dandelions are controlled in the lawn or garden in fall better than any other time of year. Read and follow label instructions for quantity. Also make sure leaves are raked prior to application so herbicide makes contact with weed leaves. This will also knock out some of the winter annuals like henbit or chickweed. These winter annuals are often bad about growing next to the house and in spring perennial beds. Though at your own risk since it is not on the label, dormant spring perennials like daffodils, tulips or peonies, will tolerate glyphosate (Roundup and other names) at 2-3 ou./gallon mixture to control winter annuals often establishing in these spots during the fall.

Fall Applied

Farm Playoffs

Fall weed control is also important for the farmer and particularly for the no-till farmer. With some fields harvested early, one must be careful to get too anxious to start fall weed control since it is best to wait until after Oct. 15. Also since there is fairly narrow window for fall weed control, depending on the weather, one should prioritize fields for fall weed control. Fields with a history of late spring burn down without fall weed control most likely have the greatest seed bank for winter annuals. Also monitor dandelion, Canada thistle quackgrass as these can be controlled in November. Fields that were yellow with cressleaf groundsel (the weed everyone last spring referred to as mustard though it was not) would be good candidates, particularly if on soils that tend to be wet and slow to warm in the spring. Effective fall weed control should be in the $6 to $12 range excluding the cost of application.

No-till farmers certainly need to pay attention to fall weed development. While no-till farmers have increased management duties, a herbicide treatment is certainly cheaper than fuel prices for tillage. Giving weeds attention now will aid in reducing habitat for black cutworm moths next spring in addition to a host of other pest issues. More importantly it will aid in maintaining a uniform surface for preparing a no-till seed bed next spring. While on the topic of uniform seed bed, no-till management begins at harvest with spreading evenly crop residue. Larger heads on today's combines make this more challenging. Even for those who are not no-till, the issue of uneven residue spreading can cause hidden field issues. Spreaders are critically important to pay attention to making sure they are doing their job well. See the recent Pest & Crop Newsletter at for an excellent table with results of multiple years of fall applied herbicide trials referred to as the "playoffs" of fall applied herbicides.

You can contact the local Purdue Extension Office by calling 829-5020 x14 in Owen County or 448-9041 in Clay County for more information or publication copies regarding this week's column topic or to RSVP for upcoming events. It is always best to call first to assure items are ready when you arrive and to RSVP for programs. While most publications are free, some do have a fee. All times listed are Eastern Time.

Upcoming Events

Oct. 11 Landlord Agreement Bi-State Workshop, Beef House, 12:30 p.m.

Oct. 19 Large Mouth Bass on Feed Workshop, Kentucky State University

Oct. 20 Sheep Shearing School, Wingate, 9 a.m.

Nov. 3 Owen Extension Annual Meeting w/ Tom Turpin, 6:30 p.m.

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